The current years work will aim at first completing work started in the current year. We will finish studying the physiological effects of several different electrode designs. Two electrode designs will be used. One electrode design which allows us to recruit motor units from the fastest to slowest motor units and one electrode which allows recruitment from the slowest to fastest motor units. The former is a more simplistic electrode design while the latter represents the physiological order of recruitment. We will study fatigue and metabolism of the hindlimb muscles of the cat during stimulation by these 2 means.. Finally, during most of the year, we will conduct a series of studies to identify the minimum number of muscles which must be stimulated in the cat hindlumb to allow 2 dimensional control of walking types of movement. This will be accomplished by recording the EMG from cat leg muscles while they walk on a treadmill.